INVESTIGADORES
AGUILAR Ramiro
congresos y reuniones científicas
Título:
Reproductive and genetic consequences of habitat fragmentation in plant populations: What do we know after two decades of research?
Autor/es:
AGUILAR RAMIRO; QUESADA MAURICIO; ASHWORTH LORENA; HERRERIAS-DIEGO YVONNE
Lugar:
Ciudad del Cabo, Sudafrica
Reunión:
Congreso; DIVERSITAS - Open Science Conference II - Biodiversity & Society; 2009
Institución organizadora:
DIVERSITAS
Resumen:
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The
loss and fragmentation of natural habitats by human activities are
pervasive phenomena in terrestrial ecosystems across the Earth and
the main current driving forces behind biodiversity loss.
Fragmentation studies in plant populations have mostly focused on
sexual plant reproductive dynamics. More recently, plant population
genetic parameters have also been thoroughly investigated in
fragmented habitats. By means of meta-analyses we reviewed the
results of 20 years of fragmentation studies around the world and
tested whether reproductive output and genetic diversity decreases in
fragmented habitats, and whether fragmentation has differential
effects depending on certain life history and ecological traits of
plants. We also tested whether certain methodological approaches used
by authors influence the ability to detect fragmentation effects.
Overall, fragmentation has large and negative effects on pollination,
plant reproduction, genetic diversity and outcrossing rates but no
effects on inbreeding coefficients. The mating system of plants,
which reflects both the degree of dependence on pollinator mutualism
and also the distribution of genetic diversity within and among
populations, explained most of the variation among the species
effect sizes. Outcrossing, self-incompatible plants showed strong
negative fragmentation effects on reproduction and allelic richness.
The rarity status of plants also determined differential
susceptibility to genetic erosion, where common and recently rare
plants were more negatively affected. Higher inbreeding coefficients
in fragmented habitats were only observed in studies analyzing
progenies. The time elapsed in fragmentation conditions significantly
influenced the results. Our results suggest that fragmentation is
shifting mating patterns towards increased selfing. We conclude that
animal-pollinated self-incompatible plants are
exceptionally vulnerable to fragmentation as a consequence of both,
ecological and genetic mechanisms.